The following navigation utilizes arrow, enter, escape, and space bar key commands. Left and right arrows move through
main tier links and expand / close menus in sub tiers. Up and Down arrows will open main tier menus and toggle through
sub tier links. Enter and space open menus and escape closes them as well. Tab will move on to the next part of the
site rather than go through menu items.
General Explanation Of The Tax Reform Act Of 1969, (H.R. 13270, 91st Congress, Public Law 91-172).